RESEARCH ARTICLE
Functional decay in tree community within tropical fragmented landscapes: Effects of landscape-scale forest cover Larissa Rocha-Santos1*, Maı´ra Benchimol1, Margaret M. Mayfield2, Deborah Faria1, Michaele S. Pessoa1, Daniela C. Talora1, Eduardo Mariano-Neto3, Eliana Cazetta1
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1 Graduate Program in Ecology and Biodiversity Conservation, Applied Ecology and Conservation Lab, State University of Santa Cruz, Ilhe´us, Bahia, Brazil, 2 School of Biological Sciences, The University of Queensland, St Lucia Campus, Queensland, Australia, 3 Botany department, Biology institute, Federal University of Bahia, Salvador, Bahia, Brazil * [email protected]
Abstract OPEN ACCESS Citation: Rocha-Santos L, Benchimol M, Mayfield MM, Faria D, Pessoa MS, Talora DC, et al. (2017) Functional decay in tree community within tropical fragmented landscapes: Effects of landscape-scale forest cover. PLoS ONE 12(4): e0175545. https:// doi.org/10.1371/journal.pone.0175545 Editor: RunGuo Zang, Chinese Academy of Forestry, CHINA Received: January 18, 2017 Accepted: March 28, 2017 Published: April 12, 2017 Copyright: © 2017 Rocha-Santos et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: LSR is grateful to Fapesb (BOL0176/ 2013) and CAPES (PDSE-BEX7518/14-5) for the doctoral studies scholarship. DF and EC is grateful to received a research productivity fellowship from CNPq (number 307221/2012-1, 305812/2015-7, respectively). This study was funded by the Brazilian Council of Science and Technology-CNPq (Proc. 563216/2010-7), Research Support
As tropical rainforests are cleared, forest remnants are increasingly isolated within agricultural landscapes. Understanding how forest loss impacts on species diversity can, therefore, contribute to identifying the minimum amount of habitat required for biodiversity maintenance in human-modified landscapes. Here, we evaluate how the amount of forest cover, at the landscape scale, affects patterns of species richness, abundance, key functional traits and common taxonomic families of adult trees in twenty Brazilian Atlantic rainforest landscapes. We found that as forest cover decreases, both tree community richness and abundance decline, without exhibiting a threshold. At the family-level, species richness and abundance of the Myrtaceae and Sapotaceae were also negatively impacted by the percent forest remaining at the landscape scale. For functional traits, we found a reduction in shadetolerant, animal-dispersed and small-seeded species following a decrease in the amount of forest retained in landscapes. These results suggest that the amount of forest in a landscape is driving non-random losses in phylogenetic and functional tree diversity in Brazil’s remaining Atlantic rainforests. Our study highlights potential restraints on the conservation value of Atlantic rainforest remnants in deforested landscapes in the future.
Introduction We are currently in the midst of a massive global extinction event [1], with the current wave of biodiversity reduction mainly occurring due to habitat loss and habitat modification [1,2]. For plants in particular, studies have shown that the synergistic effects of habitat loss and fragmentation lead to profound changes in patterns of tree species composition [3,4], richness [5–7], functional [8–11] and phylogenetic diversity [12–15], with landscape configuration and edge effects commonly identified as the key drivers of floristic decay in tropical rainforests. The amount of forest cover at the landscape-scale is currently considered an important driver of biological change, and a meaningful proxy for habitat loss [16]. The ‘habitat amount
PLOS ONE | https://doi.org/10.1371/journal.pone.0175545 April 12, 2017
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Functional decay in tree community: Effects of forest cover
foundation of the State of Bahia - Fapesb (JCB0049/2013) and State University of Santa Cruz - UESC (00220.1100.1320). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist.
hypothesis’ [17], in fact, posits that “patch size” and remnant “isolation” can be replaced by a single predictor variable—the amount of the remnant habitat found across a landscape. Moreover, the fragmentation threshold hypothesis [18,19] suggests that the amount of forest in the landscape is an important driver of species diversity, and that when forest remnants are in landscapes within higher percentages of total overall forest cover (> 50%) they are prone to maintain higher diversity than those in landscapes with less total forest cover. Under this hypothesis, patch size is also thought to contribute to biodiversity maintenance in landscapes with intermediate levels of forest cover (>30 and
Functional decay in tree community within tropical fragmented landscapes: Effects of landscape-scale forest cover Larissa Rocha-Santos1*, Maı´ra Benchimol1, Margaret M. Mayfield2, Deborah Faria1, Michaele S. Pessoa1, Daniela C. Talora1, Eduardo Mariano-Neto3, Eliana Cazetta1
a1111111111 a1111111111 a1111111111 a1111111111 a1111111111
1 Graduate Program in Ecology and Biodiversity Conservation, Applied Ecology and Conservation Lab, State University of Santa Cruz, Ilhe´us, Bahia, Brazil, 2 School of Biological Sciences, The University of Queensland, St Lucia Campus, Queensland, Australia, 3 Botany department, Biology institute, Federal University of Bahia, Salvador, Bahia, Brazil * [email protected]
Abstract OPEN ACCESS Citation: Rocha-Santos L, Benchimol M, Mayfield MM, Faria D, Pessoa MS, Talora DC, et al. (2017) Functional decay in tree community within tropical fragmented landscapes: Effects of landscape-scale forest cover. PLoS ONE 12(4): e0175545. https:// doi.org/10.1371/journal.pone.0175545 Editor: RunGuo Zang, Chinese Academy of Forestry, CHINA Received: January 18, 2017 Accepted: March 28, 2017 Published: April 12, 2017 Copyright: © 2017 Rocha-Santos et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: LSR is grateful to Fapesb (BOL0176/ 2013) and CAPES (PDSE-BEX7518/14-5) for the doctoral studies scholarship. DF and EC is grateful to received a research productivity fellowship from CNPq (number 307221/2012-1, 305812/2015-7, respectively). This study was funded by the Brazilian Council of Science and Technology-CNPq (Proc. 563216/2010-7), Research Support
As tropical rainforests are cleared, forest remnants are increasingly isolated within agricultural landscapes. Understanding how forest loss impacts on species diversity can, therefore, contribute to identifying the minimum amount of habitat required for biodiversity maintenance in human-modified landscapes. Here, we evaluate how the amount of forest cover, at the landscape scale, affects patterns of species richness, abundance, key functional traits and common taxonomic families of adult trees in twenty Brazilian Atlantic rainforest landscapes. We found that as forest cover decreases, both tree community richness and abundance decline, without exhibiting a threshold. At the family-level, species richness and abundance of the Myrtaceae and Sapotaceae were also negatively impacted by the percent forest remaining at the landscape scale. For functional traits, we found a reduction in shadetolerant, animal-dispersed and small-seeded species following a decrease in the amount of forest retained in landscapes. These results suggest that the amount of forest in a landscape is driving non-random losses in phylogenetic and functional tree diversity in Brazil’s remaining Atlantic rainforests. Our study highlights potential restraints on the conservation value of Atlantic rainforest remnants in deforested landscapes in the future.
Introduction We are currently in the midst of a massive global extinction event [1], with the current wave of biodiversity reduction mainly occurring due to habitat loss and habitat modification [1,2]. For plants in particular, studies have shown that the synergistic effects of habitat loss and fragmentation lead to profound changes in patterns of tree species composition [3,4], richness [5–7], functional [8–11] and phylogenetic diversity [12–15], with landscape configuration and edge effects commonly identified as the key drivers of floristic decay in tropical rainforests. The amount of forest cover at the landscape-scale is currently considered an important driver of biological change, and a meaningful proxy for habitat loss [16]. The ‘habitat amount
PLOS ONE | https://doi.org/10.1371/journal.pone.0175545 April 12, 2017
1 / 18
Functional decay in tree community: Effects of forest cover
foundation of the State of Bahia - Fapesb (JCB0049/2013) and State University of Santa Cruz - UESC (00220.1100.1320). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist.
hypothesis’ [17], in fact, posits that “patch size” and remnant “isolation” can be replaced by a single predictor variable—the amount of the remnant habitat found across a landscape. Moreover, the fragmentation threshold hypothesis [18,19] suggests that the amount of forest in the landscape is an important driver of species diversity, and that when forest remnants are in landscapes within higher percentages of total overall forest cover (> 50%) they are prone to maintain higher diversity than those in landscapes with less total forest cover. Under this hypothesis, patch size is also thought to contribute to biodiversity maintenance in landscapes with intermediate levels of forest cover (>30 and
